Electric heater.



W. STANLEY & H. M. SMITH.

ELECTRIC HEATER.

APPLICATION FILED JAN. 6. 1909.

Patented June 3, 1913.

Hg. 1 s 2 IT a JN YEN TURS' W NE'SQES WILLIAM STANLEX I a a I v v HERBERT M. Smzzuar.

W Maw/Z UNITED STATES PA'rEN-r mm WILLIAM STANLEY AND HERBERT M. SMITH, 0F PITTSFIELD, MASSACHUSETTS, ASSIGNORS T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC HEATER.

Specification of Letters Patent.

Patented J une3 1 9 13.

Application filed January 6, 1909. Sfripl No. 470,939.

To all whom it may concern.

Be it known that we, WILLIAM" STANLEY and HERBERT SMITH, citizens of the United States, residingat Pittsfield, in the county of Berkshire, State of Massachusetts,

have invented certain new anduseful'Im-' provements in Electric Heaters, of which the following is a specification. r

This invention relates to electric heaters and has for its object the provision of a'device of this character in which the heating unit is so arranged that the heat developed is conducted through the material to be heated in a very rapid and eflicient manner, the construction of the heating unit being very simple and durable.

Another object of our inventicin is to pro duce an electrically heated Ireceptacle for heating fluids in which the heatin unit is,

as nearly as possible, surrounde by the fluid to be heated.

In. carrying out our invention we provide a unit having its bottom recessed, the recess extending upward so'that the fluid will be' in both sides of the unit. The recess may be in the form of a ring and the unit is s1mi-' larly shaped and adapted to fit into the re cess. The unit is of the independent, selfcontained type mounted upon a'sultable base arranged to be screwed or otherwise secured in the recess.

Other objects of our invention will appear in the course of the following specification,

, a receptacle of suitable material having its bottom recessed as at 11. This recess may be of any desired form, but for the purpose of convenience we have shown it annular in form, the sides of the recess projecting upward parallel with the sides of the. vessel. A ring shaped heatingunit 12 is arranged so as to fit snugly into the recess 11, so as to be in intimate thermal relation with the me rounded b delivered from both sides of the heated ribitl tal-lic bottom of the receptacle. This unit we have shown for the purpose of illustratIOIT'fiS made of a strip of insulating material 13', preferably mica, bent in the form of a ring. A high resistance ribbon 14 is wound spirally around this ring and placed between] two outside strips 15 ofmica or other insulating material and the whole surmounted in a base of insulating material 17, either 'by being molded in or in any desired manner. Terminals 18 are brought out through the insulating material to insulating block 19 from which project the usual terminal pins 20. A metallic casing 21 issecured to this block so as to project up- "ward, as shown. This c. Zing is made of such a diameter that it will engage the sides of the receptacle. Screw threads 22 are provided so as to screw the casing on to the receptacle. The unit is thusforced up into the receptacle so that the fluid substantially surrounds the unit, permitting heat to be I a metal; casing 16, bent in the U-sha-ped orm. This complete ring is then bon, thus insuring a minimum thermal lag in raisin the temperature of the liquid in the vesse, and preventing (lama e to the unit from overheating even if t e vessel runs dry. and permitting the unit to be run at higher current density with greater heat- I gest themselves to those skilled'in the art,

without departing from the spirit of ,our invention, the scope of which is set'forth in the annexed claims.

What we claini as new and desire 'tdsecure by Letters Patent of the United States, is

1. An electric heater comprising a receptacle having its bottom bent upward to form an annular recess, an annular heating unit arranged to enter said recess so as to be in intimate thermal relation with the walls thereof, and means for securing the unit within the recess.

-2. An electric heater com' rising a receptac e having a bottom provi ed with an up wardly extendin annular recess whose walls integral with the bottom of the recepand an annular heating unit secured .to the receptacle and extending intc the;

arranged to enter said recess so-as to'tbein thermal relation with the-Walls thereof,

a base for said heatingunit, and means for securing the; base to the bottom ofthe receptacle. I

4. An electric heater comprising a 'recep-- tacle having its bottom bent up Ward'to for-1n an annular recess, an annular heating unit arranged to enter said recessso; as to be in thermal relation with the walls thereof, a base for said unit having-fixed' terminal connections secured thereto, and meansifer securing said base to receptacle. I 1 I 5. An electric heating deviee,--c0mprising' a cylindrical heating unit providing me-' tallic outer and inner. walls, and means there between to heat said Walls, a utensil having its bottom shaped to provide an upwardly extending, outwardly bpeziing, {annular chamber-ta receiv ei said heating unit,- the metallic Wails 10f said (heating unit "contacting'with the walls efsaidfbottom chamber,

bottgm chamber, I v. I Q16 An'electric heater comprisinga receptionv'cf contact with the said walls; 10 the tacle having an annular-lycontinueus cyli i i "drical rec'essWithvertical innerand outer walls extended inwardlyfrojniflthe therwiseaas uniform wall of the receptacletbf previde within the receptacle relatively wide unobstruc ted liquid spaces separated by the mus;-

of the recess, and a our-hands this thirtyfirst day of December,

WILLIAM STANLEY. HERBERTM. SMITH.

R-G. LnRAM IE.

I cylindrical Zheatin'g' -unit I arranged tojenter-said'rece'ss, ,5- In witness Wher'eof,;we have'he'reunto" set Copies of this patent may be obtained for five cents each. by addressing the Ccmm'issipner bf ratents.

Washington, D. C." I 

